1. Field of the Invention
The present invention relates to an image-capturing system.
Priority is claimed on Japanese Patent Application No. 2009-236419, filed on Oct. 13, 2009, the content of which is incorporated herein by reference.
2. Description of Related Art
Recently, virtual microscopes have become well known in the field of pathology such as in cell and tissue diagnosis. The virtual microscopes can capture an image of the entire glass slide on which a sample is placed, digitalize the captured image, display the digitalized image on a monitor of a personal computer, and operate as if the sample were observed with an actual microscope.
In a microscope system acquiring image data to be used in the virtual microscope, it is required to acquire the image data with a high resolution and at a high speed. Therefore, a microscope system using a one-dimensional scanner camera with an imaging device in which plural pixels are arranged in one dimension is proposed (for example, see PCT Japanese Translation Patent Publication No. 2004-514920).
In such a microscope system, a glass slide mounted on a stage and having a sample placed thereon is moved in a horizontal direction, whereby image data of the glass slide is acquired with a one-dimensional scanner camera. In this case, since the image data in the X-axis direction (a sub scanning direction of a line sensor built into the one-dimensional scanner camera) of the glass slide corresponding to a visual field of observation of the one-dimensional scanner camera can be acquired by scanning, the image data of the glass slide can be consequently acquired at a high speed.
A specific example where a glass slide is scanned to acquire image data of the glass slide by the use of the one-dimensional scanner camera in the microscope system will be described below. FIG. 23 is a diagram illustrating the configuration of a microscope system using a one-dimensional scanner camera.
The microscope system includes a light source 1102, a stage 1103, a driving device 1104, a line sensor 1105, and an optical system 1106. A glass slide 1101 is mounted on the stage 1103.
A sample is placed on the glass slide 1101. The light source 1102 illuminates the glass slide 1101. In the example shown in FIG. 23, the glass slide 1101 is transmissively illuminated by the light source 1102. The driving device 1104 moves the stage 1103 in the horizontal direction, that is, moves the stage 1103 in the XY direction. The line sensor 1105 is constructed by an imaging device receiving light from the glass slide 1101 and converting the received light into an electrical signal. The optical system 1106 includes plural lenses and enlarges and focuses an image of the glass slide 1101 on a face of the line sensor 1105. Therefore, the light from the glass slide 1101 is input to the line sensor 1105 through the optical system 1106.
FIG. 24 shows a trace of a visual field of observation of the line sensor 1105 when the line sensor 1105 acquires image data of the glass slide 1101. By moving the stage 1103 in the horizontal direction, an area 1205 (the visual field of the observation) from which the image data is acquired by the line sensor 1105 is also moved. In an initial state, the driving device 1104 moves the stage 1103 so that the line sensor 1105 is located at a position for acquiring the image data of a left-upper area 1206. In FIG. 24, the direction from the left side to the right side which is the sub scanning direction of the line sensor 1105 is defined as the X-axis direction. The direction from the lower side to the upper side which is the main scanning direction of the line sensor 1105 is defined as the Y-axis direction. The direction perpendicular to FIG. 24 is defined as the Z-axis direction.
Initially, the driving device 1104 moves the stage 1103 in an X1 direction parallel to the X-axis direction. Accordingly, the line sensor 1105 performs the scanning as indicated by arrow a. Therefore, the microscope system acquires the image data of an area 1201-1. Subsequently, the driving device 1104 moves the stage 1103 in an Y1 direction parallel to the Y-axis direction by a distance in the longitudinal direction (the main scanning direction) of the line sensor 1105 or a distance smaller than the distance in the longitudinal direction of the line sensor 1105. Subsequently, the driving device 1104 moves the stage 1103 in an X2 direction parallel to the X-axis direction. Accordingly, the line sensor 1105 performs the scanning as indicated by arrow b. Therefore, the microscope system acquires the image data of an area 1201-2.
The microscope system repeatedly performs the above-mentioned operation. That is, the line sensor 1105 performs the scanning operation in the order of arrows a, b, c, . . . , and n shown in FIG. 24, whereby the microscope system acquires partial image data of areas 1201-1 to 1201-n of the glass slide 1101. The microscope system acquires the entire image data of the glass slide 1101 by synthesizing the acquired partial image data of the areas 1201-1 to 1201-n. 